Tcl
Tcl
Decrypt a SAML Response
See more Encryption Examples
Demonstrates how to decrypt a SAML response.Chilkat Tcl Downloads
load ./chilkat.dll
set success 0
# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.
# This example decrypts this SAML response:
# <?xml version="1.0" encoding="UTF-8" ?>
# <saml2p:Response Destination="https://deskflow-asp2.com/ubc/ubcdfe.dll/cwlacs" ID="_e4585eaeedbcaf7c24dff7f1ee2499f5" IssueInstant="2018-10-11T17:46:20.727Z" Version="2.0" xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol">
# <saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">https://authentication.stg.id.ubc.ca</saml2:Issuer>
# <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
# <ds:SignedInfo>
# <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
# <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/>
# <ds:Reference URI="#_e4585eaeedbcaf7c24dff7f1ee2499f5">
# <ds:Transforms>
# <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
# <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
# </ds:Transforms>
# <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
# <ds:DigestValue>1ui22tqFyYEOoWI19CMwz4n+ynxNjLDGdTeRMdi60EU=</ds:DigestValue>
# </ds:Reference>
# </ds:SignedInfo>
# <ds:SignatureValue>ROg7FXV6vsp8socVhdo76/i7cRHGGKIveAiScKdujZT0QrHVqIvvbZ/RnwvEMJ9H9i/kJFAQA171
# Eo2kDjSdvNFQ/YcKaJUwMtAwT05yVatGV42RZKEf7ME+vpcCTR1LWZdrhat1FWCg1MNQwNWB0EL5
# fEP2a4jAcSTB8tFbjTAHsv7IWC39E5RVv99mACYXLa7iGZLtORANZxgYu5qQgmH6pUkI6Z1cpmf+
# m9mIjKM6LF0EvLfWOBWL6udZ+GsHPOLjVTJg+1S0xb9FQCYDVW1QhbjSS0icKHKTNNbrsaxllVDY
# m4q27YQjRh+XxugPgvsZ61Pxlto8Jbg+6jUlMQ==</ds:SignatureValue>
# <ds:KeyInfo>
# <ds:X509Data>
# <ds:X509Certificate>MIIDTTCCAjWgAwIBAgIVAJccYyIV6wly8XyddumpgnHMJ2JLMA0GCSqGSIb3DQEBCwUAMCcxJTAj
# BgNVBAMMHGF1dGhlbnRpY2F0aW9uLnN0Zy5pZC51YmMuY2EwHhcNMTcwMzAxMTk1NDM0WhcNMzcw
# ...
# xUuh6HuHKIwQqHBz7udxbH3Zbb6jXGDJjiDHt1LRJ8xbVisFIcDlIwsGQQi0HeEJfx4P</ds:X509Certificate>
# </ds:X509Data>
# </ds:KeyInfo>
# </ds:Signature>
# <saml2p:Status>
# <saml2p:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/>
# </saml2p:Status>
# <saml2:EncryptedAssertion xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">
# <xenc:EncryptedData Id="_314d80b9cf02d8eda8d686a6ffd626cf" Type="http://www.w3.org/2001/04/xmlenc#Element" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
# <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"/>
# <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
# <xenc:EncryptedKey Id="_d7b6da6fb59a627ebb4a96928441ab79" Recipient="https://ubcdfe.deskflow-asp2.com" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
# <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
# <ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" xmlns:ds="http://www.w3.org/2000/09/xmldsig#"/>
# </xenc:EncryptionMethod>
# <ds:KeyInfo>
# <ds:X509Data>
# <ds:X509Certificate>MIICuzCCAiQCCQD3bpigRnKMSzANBgkqhkiG9w0BAQsFADCBoTELMAkGA1UEBhMCQ0ExEDAOBgNV
# BAgMB09udGFyaW8xEDAOBgNVBAcMB1Rvcm9udG8xJjAkBgNVBAoMHVRhY3RpY2FsIEJ1c2luZXNz
# ...
# kVRcHd1UK3q7G8FoykWjdQz/0EoMTfEZ+Md56mLOe48eMUZV2ONZuL1kDCEKw1UwkaDQI4Pf8pzx
# 82b9rgw9wBDtvu5eFPlUGEGIBw==</ds:X509Certificate>
# </ds:X509Data>
# </ds:KeyInfo>
# <xenc:CipherData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
# <xenc:CipherValue>BNHfUOpgdPE5BgpN2VIZIDthMAv1rxk91qVnWyCZOG9bmUKChJtTUqMpndot7VJwYuyKFshkAdnT
# D79KGdlSA1xHKcVeZXXzDWglqSyYjzhDCsyOhPaI4HelMFgCLwyFz89uEpUpqlvfl8ol3Am/XnzQ
# Vp7V7oS76hocjUI51Qs=</xenc:CipherValue>
# </xenc:CipherData>
# </xenc:EncryptedKey>
# </ds:KeyInfo>
# <xenc:CipherData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#">
# <xenc:CipherValue>R6l7tmbnXrOfBgB8lA3KnwLYsLH5ZO5omQ7Hp5K05atzw2o55xmCXVMYhNneFxMtxUh6raEyHeZX
# PTZNgWrvdqc4GYND/R7MhRrJzk9OAq1WyoOXwbtRpwNDwWA4N2IuprPQJbvjVxaw/PesZMZwZqlp
# ...
# zm9zAxahyu8Ooe8M4r3HN2cY0JxxxkZtDiulbnyA+rRtXfBRJtangvFQ4iFAnzM/Yg9hMyW9jcu0
# S7FzuRB9ONMxi+nh0IFWgqp+</xenc:CipherValue>
# </xenc:CipherData>
# </xenc:EncryptedData>
# </saml2:EncryptedAssertion>
# </saml2p:Response>
# The sample encrypted SAML response and RSA private key are available online:
set http [new_CkHttp]
set sbSamlResponse [new_CkStringBuilder]
set sbPrivateKeyPem [new_CkStringBuilder]
set success [CkHttp_QuickGetSb $http "https://chilkatdownload.com/data/samlresponse.xml" $sbSamlResponse]
if {$success == 1} then {
set success [CkHttp_QuickGetSb $http "https://chilkatdownload.com/data/samlresponse_privkey.pem" $sbPrivateKeyPem]
}
if {$success == 0} then {
puts [CkHttp_lastErrorText $http]
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
exit
}
set xml [new_CkXml]
CkXml_LoadSb $xml $sbSamlResponse 1
# Load the RSA private key..
set privkey [new_CkPrivateKey]
set success [CkPrivateKey_LoadPem $privkey [CkStringBuilder_getAsString $sbPrivateKeyPem]]
if {$success == 0} then {
puts [CkPrivateKey_lastErrorText $privkey]
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
delete_CkXml $xml
delete_CkPrivateKey $privkey
exit
}
# Prepare an RSA object w/ the private key...
set rsa [new_CkRsa]
set success [CkRsa_UsePrivateKey $rsa $privkey]
if {$success == 0} then {
puts [CkRsa_lastErrorText $rsa]
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
delete_CkXml $xml
delete_CkPrivateKey $privkey
delete_CkRsa $rsa
exit
}
# RSA will be used to decrypt the xenc:EncryptedKey
# The bytes to be decrypted are in xenc:CipherValue (in base64 format)
set encryptedAesKey [CkXml_getChildContent $xml "saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:CipherData|xenc:CipherValue"]
if {[CkXml_get_LastMethodSuccess $xml] != 1} then {
puts "Encrypted AES key not found."
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
delete_CkXml $xml
delete_CkPrivateKey $privkey
delete_CkRsa $rsa
exit
}
puts "Encrypted AES key (base64) = $encryptedAesKey"
set bdAesKey [new_CkBinData]
CkBinData_AppendEncoded $bdAesKey $encryptedAesKey "base64"
set sbRsaAlg [new_CkStringBuilder]
CkStringBuilder_Append $sbRsaAlg [CkXml_chilkatPath $xml "saml2:EncryptedAssertion|xenc:EncryptedData|ds:KeyInfo|xenc:EncryptedKey|xenc:EncryptionMethod|(Algorithm)"]
puts "sbRsaAlg contains: [CkStringBuilder_getAsString $sbRsaAlg]"
if {[CkStringBuilder_Contains $sbRsaAlg "rsa-oaep" 1] == 1} then {
CkRsa_put_PkcsPadding $rsa 0
}
set success [CkRsa_DecryptBd $rsa $bdAesKey 1]
if {$success == 0} then {
puts [CkRsa_lastErrorText $rsa]
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
delete_CkXml $xml
delete_CkPrivateKey $privkey
delete_CkRsa $rsa
delete_CkBinData $bdAesKey
delete_CkStringBuilder $sbRsaAlg
exit
}
puts "Decrypted AES key (hex) = [CkBinData_getEncoded $bdAesKey hex]"
# Get the encrypted XML (in base64) to be decrypted w/ the AES key.
set encrypted64 [CkXml_getChildContent $xml "saml2:EncryptedAssertion|xenc:EncryptedData|xenc:CipherData|xenc:CipherValue"]
if {[CkXml_get_LastMethodSuccess $xml] != 1} then {
puts "Encrypted data not found."
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
delete_CkXml $xml
delete_CkPrivateKey $privkey
delete_CkRsa $rsa
delete_CkBinData $bdAesKey
delete_CkStringBuilder $sbRsaAlg
exit
}
set bdEncrypted [new_CkBinData]
CkBinData_AppendEncoded $bdEncrypted $encrypted64 "base64"
# Get the symmetric algorithm: "http://www.w3.org/2001/04/xmlenc#aes128-cbc"
# and set the symmetric decrypt properties.
set crypt [new_CkCrypt2]
set sbAlg [new_CkStringBuilder]
CkStringBuilder_Append $sbAlg [CkXml_chilkatPath $xml "saml2:EncryptedAssertion|xenc:EncryptedData|xenc:EncryptionMethod|(Algorithm)"]
if {[CkStringBuilder_Contains $sbAlg "aes128-cbc" 1] == 1} then {
CkCrypt2_put_CryptAlgorithm $crypt "aes"
CkCrypt2_put_KeyLength $crypt 128
CkCrypt2_put_CipherMode $crypt "cbc"
# The 1st 16 bytes of the encrypted data are the AES IV.
CkCrypt2_SetEncodedIV $crypt [CkBinData_getEncodedChunk $bdEncrypted 0 16 "hex"] "hex"
CkBinData_RemoveChunk $bdEncrypted 0 16
}
# Other algorithms, key lengths, etc, can be supported by checking for different Algorithm attribute values..
CkCrypt2_SetEncodedKey $crypt [CkBinData_getEncoded $bdAesKey "hex"] "hex"
# AES decrypt...
set success [CkCrypt2_DecryptBd $crypt $bdEncrypted]
if {$success == 0} then {
puts [CkCrypt2_lastErrorText $crypt]
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
delete_CkXml $xml
delete_CkPrivateKey $privkey
delete_CkRsa $rsa
delete_CkBinData $bdAesKey
delete_CkStringBuilder $sbRsaAlg
delete_CkBinData $bdEncrypted
delete_CkCrypt2 $crypt
delete_CkStringBuilder $sbAlg
exit
}
# Get the decrypted XML
set decryptedXml [CkBinData_getString $bdEncrypted "utf-8"]
puts "Decrypted XML:"
puts "$decryptedXml"
# The decrypted XML looks like this:
# <saml2:Assertion xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion" ID="_226e565c548db7986d165d7d969b48b4" IssueInstant="2018-10-11T17:46:20.727Z" Version="2.0">
# ...
# ...
# ...
# </saml2:Assertion>
set xmlAssertion [new_CkXml]
CkXml_LoadXml $xmlAssertion $decryptedXml
# Replace the saml2:EncryptedAssertion XML subtree with the saml2:Assertion XML.
# xmlEncryptedAssertion is a CkXml
set xmlEncryptedAssertion [CkXml_FindChild $xml "saml2:EncryptedAssertion"]
CkXml_SwapTree $xmlEncryptedAssertion $xmlAssertion
delete_CkXml $xmlEncryptedAssertion
# The decrypted XML assertion has now replaced the encrypted XML assertion.
# Examine the fully decrypted XML document:
puts "Full XML SAML document with decrypted assertion:"
puts [CkXml_getXml $xml]
delete_CkHttp $http
delete_CkStringBuilder $sbSamlResponse
delete_CkStringBuilder $sbPrivateKeyPem
delete_CkXml $xml
delete_CkPrivateKey $privkey
delete_CkRsa $rsa
delete_CkBinData $bdAesKey
delete_CkStringBuilder $sbRsaAlg
delete_CkBinData $bdEncrypted
delete_CkCrypt2 $crypt
delete_CkStringBuilder $sbAlg
delete_CkXml $xmlAssertion